BRACHI0P0DA — 0RTHW7E. 



265 



198. R. vanuxemi Hall. (Fig. 320, a-c.) Devonic. 

 Subcircular. Pedicle valve nearly flat, becoming moderately 



convex near the beak. Brachial valve convex. 



Onondaga-Hamilton of New York, Ohio, Michigan, Illinois, 

 Iowa, Ontario. 



199. R. leucosia Hall. (Fig. 320, d-c.) Devonic. 

 Broadly ovate with pointed beak. Both pedicle and brachial 



valves convex. 



Hamilton of New York, Maryland. 



200. R. penelope Hall. (Fig. 320,/-^.) Devonic. 

 Large, subcircular. Brachial valve regularly convex and slightly 



depressed medially. Pedicle valve depressed convex above, be- 

 coming flat or concave toward the margin but lacking a sinuosity 

 in front. Beaks not prominent. 

 Hamilton of New York. 



201. R. thiemei (White). Devonic and Mississippic. 

 Usually a little wider than long. Convex at beak but flattened 



toward the front owing to a broad, faint sinus in each valve. Beak 

 of pedicle valve short, elevated and slightly incurved beyond the 

 cardinal area. Brachial valve the deeper. Differs from R. vanux- 



Fig. 320. a-c, 

 (After Hall.) 



Rhipidomella vanuxemi 



